Untitled

<html>
<head>
	<script>
	function chooseBoard(idNumber){
	document.getElementById("toAnotherSelect").innerHTML = idNumber;
	}
	</script>
</head>

<body>

<select onchange="chooseBoard(this.value)">
  <option name="board" value="0"  >STM32</option>
  <option name="board" value="1">raspberry pi 0</option>
  <option name="board" value="2" >raspberry pi 2</option>
  <option name="board" value="3" >raspberry pi 3</option>
</select>

<p id="toAnotherSelect">0</p>

</body>

</html>